The present invention relates to a thermostatic valve having a working element whose housing is stationarily held by a holder constructed as a sheet metal preform and whose extendable working piston is provided with a valve disk which is loaded by means of a closing spring in the direction of a valve seat, the holder of the housing being provided with a flange which can be clamped in between a connection sleeve and a housing part.
In a thermostatic valve of the above-described type, which is known on the basis of prior public use, three sheet metal preforms are provided which together form the holder for the housing of the thermostatic working element and contain a flange and a cage-type abutment for the closing spring. The known thermostatic valve is used for controlling the coolant temperature of an internal-combustion engine of a motor vehicle. It forms a constructional unit which, when the motor vehicle engine and its connections are mounted, must be installed by the motor vehicle manufacturer between a connection sleeve or the like and a housing.
An object of the present invention is to provide a thermostatic valve improved in such a manner that its installation into a motor vehicle engine or the like is facilitated and mounting errors are largely excluded.
This and other objects are achieved in that the holder of the housing of the working element and the connection sleeve are connected with one another for producing a transportable constructional unit, in that the connection sleeve is provided in its interior with one or several abutments for the closing spring, and in that the connection between the holder and the connection sleeve is dimensioned such that it has a holding force which exceeds a prestressing force of the closing spring.
With the present invention, it is achieved that, as early as in the manufacturing plant in which the thermostatic valve is produced, its installed position with respect to the connection sleeve is determined. In a later connection to a housing of an internal-combustion engine or a water pump or the like, the mounting is therefore facilitated, thereby avoiding mounting errors. The mounting can thus be carried out by untrained personnel or personnel with little training, possibly also by means of robots. In addition, a simplification is obtained because another sheet metal preform will not be necessary since the connection sleeve is simultaneously utilized as an abutment for the closing spring. The connection sleeve and the thermostatic valve therefore form not only a transportable constructional unit but also a functional unit.
In certain embodiments of the invention, the holder is provided behind the flange with a closed collar which is assigned as a valve seat to the valve disk. This reduces the manufacturing costs because, in comparison to the known thermostatic valve, a sheet metal preform is not required, specifically the sheet metal preform which forms a valve seat. The holder, which is manufactured as a sheet metal preform, therefore has a double function.
The connection sleeve is a plastic preform in certain embodiments. Although, as a rule, the connection sleeve will be manufactured as a light-metal diecast preform, it may also be advantageous for certain applications and particularly for reasons of manufacturing costs to manufacture the connection sleeve as a plastic preform.
In certain embodiments of the invention, the holder and the connection sleeve are provided with connection elements which are engageable with one another. As a result, it is achieved that no additional connection elements are required which must be manufactured and mounted separately. The assembly and the manufacturing are therefore simplified.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.